1. Field of the Invention
This is a new process for making bispicolylamine from cyanopyridines and hydrogen. Palladium on .alpha.-alumina is used as the catalyst.
2. Prior Art
Volkova et al. teach that cyanopyridines are hydrogenated in the presence of palladium (or palladium on carbon) to form the corresponding picolylamines (i.e., aminomethylpyridines). See Volkova et al.: Chemical Abstracts, 79: 42296n; 80: 120705q; 81: 49570x; 83: 28065n; and 83: 113388q. Matsumoto et al. (Chemical Abstracts, 82: 156097r) teach that 2,6-biscyanopyridines are hydrogenated to form the corresponding 2,6-bis(aminomethyl)pyridines as the trihydrochloride salts when the reaction is conducted over palladium on carbon using hydrochloric acid/methanol as the hydrogenation medium. These references indicate that palladium and palladium on carbon are very effective catalysts in the reaction and produce the corresponding picolylamines selectively.
Garrou and Hartwell teach in U.S. Pat. No. 4,080,338 that bispicolylamines are prepared by reacting (a) cyanopyridine with (b) hydrogen in the presence of a catalytic amount of (c) a palladium or carbon catalyst which has been preconditioned by contact with a reacting mixture of (a) and (b) for a time sufficient to cause said catalyst to preferentially produce bispicolylamine. The reaction is normally conducted under autogenous or superatmospheric pressure at a temperature of from about 20.degree. C. to about 75.degree. C. in a lower alkanol (e.g., methanol) as the reaction medium.